Artificial hand

ABSTRACT

This hand is provided with two clamping jaws (1,2) movable toward or respectively apart from each other, each of which is mounted in each case to a hinge quadrangle (3, 4). At each clamping jaw (1, 2) there is supported a gripping plate (8, 9) tiltable around an axis (5, 6) vertical to the jaw axis. The two hinge quadrangles (3, 4) can be rotatably supported jointly by an axis running parallel to the hinge axes of the hinge quadrangles (3, 4), however, also the two hinge quadrangles can be jointly tiltable around one axis, which runs vertical to the hinge axes (FIG. 3).

CROSS REFERENCE TO RELATED APPLICATION

This application is a national phase application of PCT applicationPCT/AT80/00015 filed May 25, 1980 and based upon Austrian applicationSer. No. A 3735/79 filed May 21, 1979 under The InternationalConvention.

FIELD OF THE INVENTION

The invention relates to an artificial hand, which is provided with twoclamping jaws or the like movable towards each other and away from eachother for gripping of objects. Each clamping jaw is mounted to a hingequadrangle and more particular to a hingeparallelogram.

OBJECT OF THE INVENTION

It is an object of the invention to form such a hand so that the objectgripped (after the gripping) can be brought into as many differentpositions as possible.

SUMMARY OF THE INVENTION

This object is achieved with an artificial hand having a gripping plate,preferably provided with a groove, at each clamping jaw, the grippingplate being tiltable around an axis perpendicular to the plane of thejaw. The two hinge quadrangles can be tilted jointly around an axiswhich is parallel to the hinge axes of the hinge quadrangles or the twohinge quadrangles can be jointly tiltable by preferably 180° around anaxis directed perpendicularly to the hinge axis. The tiltabledisposition of the gripper plate at the clamping jaws allows the grippedobject to be brought into arbitrary positions within the tilting rangein a plane parallel to the clamping jaws. If in addition the two hingequadrangles jointly are tiltable around a joint axis directed parallelto the hinge axes of the hinge quadrangles, then the plane of thegripper plates is itself tiltable. In addition or instead of providingtiltability of the two hinge quadrangles around the axis directedparallel to the hinge axes, the two hinge quadrangles can also bejointly tiltable around an axis directed perpendicular to the hinge axesand it allows for movability to place a gripped object in additionalspacial positions.

A constructive simplification of the construction of the gripping handand additional advantageous relations for the control of the highclamping forces by only small parts is achieved, if the axis parallel tothe hinge axes, around which axis the two hinge parallelograms arejointly tiltable, is also an ideal hinge axis belonging to both jointly.A ring can be disposed concentrically to this axis which carries anadditional hinge axis of the hinge parallelograms and the parallelogramare guided rotatably on the ring, for example by circular bearingsdisposed concentrically to the ring.

In order to achieve a simply constructed drive for the clamping of anobject there can be provided as an additional feature of the invention apinion at the drive for the tilting together or apart of the of the twohinge quadrangles. The pinion can engage at the same time two toothedsegments, one of which is attached to the guide of each hingequadrangle.

A preferred further feature comprises in this case that a motor with adrive is provided along the axis, which drives via a gearwheel thepinion along the axis and in particular that the drive disposed alongthe axis is switchable such that as desired the pinion or the ring canbe driven.

In another embodiment of the invention there is provided for a puremanual operation a manual drive such as a handwheel for tilting of thetwo clamping plates or for the joint rotation of the hinge quadranglesaround the axis.

It is an advantage for the practical handling, if in a practicalembodiment of the invention one of the gripper plates is drivable by amotor and preferably by a bevel gear drive, whereas the other gripperplate is displaced by an object clamped between the two gripper plates,for example engaging in grooves of the two gripper plates.

In a further embodiment of the invention in the free space between theclamping jaws or the hinge quadrangles carrying them there is providedan exchangeable bridge covering the drive parts, which bridge preferablyis provided at its upper side with groove-like guide surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional features, details and advantages of the invention result inthe following from the description by way of two embodiments shown inthe drawing; in the drawing:

FIG. 1 is a schematic plan view of an artificial hand in accordance withthe invention;

FIG. 2 is a horizontal projection corresponding to FIG. 1;

FIG. 3 is a schematic illustration of the kinematics of the hand inaccordance with the present invention;

FIG. 4 is a detail of the region A shown in FIG. 2 in an enlarged scale;and

FIG. 5 is a side view and FIG. 6 is a section along line VI--VI ofanother embodiment.

SPECIFIC DESCRIPTION

The artificial hand in accordance with the present invention is providedwith two clamping jaws 1,2 movable toward each other and away from eachother.

The kinematics of the drive for the motion of these clamping jaws 1 and2 is herein effected by hinge quadrangles 3,4 (see FIG. 3), which areformed such as to assure that the two clamping jaws 1 and 2 in eachposition are maintained substantially parallel to each other. Inparticular the hinge quadrangles 3 and 4 are formed substantially ashinge parallelograms as can be seen from FIG. 3.

Each clamping jaw 1 and 2 is provided with a gripper plate 8,9 tiltablearound an axis 5,6 perpendicular to the jaw plane. In order to allow forgood support for rod shaped articles 23 such as lead pencils and thelike by the gripper plates 8 and 9, these gripper plates are providedwith mutually confronting grooves 7.

Both hinge quadrangles 3 and 4 are jointly swingable around an axis 10,which runs parallel to the hinge axes of the hinge quadrangles 3, 4.

In addition the two hinge quadrangles 3, 4 are jointly movable around anaxis 11, which runs perpendicular to the axes of the hinge quadrangles3, 4.

As can be recognized from FIG. 2, the hinge quadrangles 3,4 can betilted around an axis 11 through an angle of 180°. The gripper plates 8and 9 can be provided with hook-like extensions to allow the grippinghand to engage loops, eyelets and the like, which are displaced on theobjects to be manipulated.

The axis 10, around which the two hinge quadrangles are jointlytiltable, is also one hinge axis jointly belonging to the two, that isextensions of the limbs 16, 17 run through this axis 10 (FIG. 3). A ring12 concentrically disposed to the axis 10 is provided for receiving thehinge axes of the hinge quadrangles. The parallelogram limbs 16, 17,which run substantially parallel to the parallelogram limbs 15, 18tiltably disposed relative to the ring 12, are tiltably guided on thering 12. For the guiding herein the limbs 16, 17 are provided with (inpart shown in dashed lines) ring bearings 19, 20, which are supported byrollers or like bodies next to each other.

As is shown in FIG. 4, one gripper plate 9 can be driven by a motor 21via a bevel gear drive 22. The other gripper plate P is entrained by theclamped object 23 between the gripper plates 8,9. The two tilt axes 10and 11, around which the hinge quadrangles 3 and 4 can be jointlytilted, preferably intersect each other. Each (not shown) drive, withwhich the two hinge quadrangles 3, 4 can be tilted toward and away fromeach other around the axis 10, is provided with a motor with drive andpinion 24, which at the same time engages two toothed segments 25, 26,of which one in each case is attached to the limb 16 and 17,respectively. Advantageously, this drive is switchable in the axis 10for driving either the ring 12 or via a gearwheel 33 the pinion 24.Particularly advantageous is here the provision of a spin-resistantdrive.

In FIG. 4 the angle is designated as α with which the gripper plates 8,9 are tiltable around the axis 5 or respectively 6 disposed vertical tothe clamping jaws 1 or respectively 2. This angle is preferably 90°. Theaxis 10 running parallel to the hinge axes allows a tilting by an angleβ of the magnitude of again about 90°. The two hinge quadrangles 3, 4can also be tilted around the axis 10.

The gripper plates 8, 9 can be dismountably connected, that isreplaceably connected, with the clamping jaws 1, 2. In order to be ableto employ for special manipulations differently formed gripper plates 8,9, these are attached to the clamping jaws 1, 2 by way of a simplydisconnectable connection, such as for example by a catch device.

In addition, a handwheel 28 is provided for tilting of the two clampingjaws 1, 2 or respectively for the joint tilting of the hinge quadrangles3,4 around an axis 10. The handwheel 28 is provided with grippingrecesses 29. This handwheel 28 is rotatably supported around the axis 10and is coupled solidly or for each case with the drive for the hingequadrangles; this way it allows a manual drive or respectively a manualamplification of the gripping force built up by this drive.

The gearwheel drive 22 can also be replaced by a catch provision, by theaid of which the gripper plates 8, 9 are fixed in the desired position.

In the free space between the clamping plates 1, 2 or respectively thehinge quadrangles 3, 4 supporting them there is removably disposed abridge 30 in the embodiment shown in FIGS. 5 and 6 above the drive parts24,25, 26. The bridge protects these drive parts and the side housingparts against excessive force and damage and is provided at its upperside with prismatic or groove-like guide surfaces 31 for depositingclamped, and in particular elongated articles such as the hammerindicated in FIG. 6 in dot-dash lines. Important is here again theexchangeability of this bridge 30, which allows various resting prism,additional tensioning surfaces or special functions with tool likecharacter such as cutting and the like, to be used.

In order to allow for releasing of a clamped in object, which is fixedby a gripping force or by a locking mechanism, even in case the drivesystem is interrupted or is defective, then advantageously a safetycoupling not shown can be coordinated with the drive for the hingequadrangles 3,4, which for example can be actuated by a lever from theoutside, whereby the two clamping jaws 1,2 are decoupled from the drivesystem and thereby become freely rotatable around the axis 10.

The control of the tilting motion around the axis 10 can be providedeither actively by way of a motor and a self-blocking drive or by hand,wherein in the latter case a fixation in catch position or stepless byfrictional coupling can be provided.

I claim:
 1. An artificial hand comprising:a support rotatable about afirst axis; a ring mounted on said support for rotation about a secondaxis constituting the axis of said ring and perpendicular to said firstaxis; a pair of hinge quadrangles each having a first limb pivotallyconnecting the said ring for rotation therewith, a second limb generallyparallel to said first limb and having an end displaceable along saidring whereby extensions of said second limbs intersect at said secondaxis whereby said quadrangles virtually have a common pivot axiscoinciding with said second axis, and a third limb articulated to saidfirst and second limbs; respective clamping jaws pivotally mounted onthe respective hinge quadrangles and tiltable relative thereto about arespective third axis generally transverse to a plane common to saidfirst and second axes, said jaws being juxtaposed for engagement ofobjects therebetween and being displaced toward and away from oneanother by swinging movement of said second limbs toward and away fromone another; and means for angularly displacing at least one of saidjaws about the respective third axis relative to the respective hingequadrangle and for relatively displacing said second limbs of said hingequadrangles.
 2. The artificial hand defined in claim 1 wherein each ofsaid second limbs is guided on said ring by a circular bearing disposedcoaxially with said ring.
 3. The artificial hand defined in claim 2wherein said means for relatively displacing said limbs of said hingequadrangles includes a pinion and respective gear segments connected tosaid second limbs and meshing with said pinion.
 4. The artificial handdefined in claim 2 further comprising drive means including a motor, agear driven by said motor and a further gear rotatable about said secondaxis and meshing with the motor driven gear for rotating said ring onsaid support about said second axis.
 5. The artificial hand defined inclaim 2, further comprising a hand wheel rotatable about said secondaxis and connected with said ring for tilting same about said secondaxis.
 6. An artificial hand defined in claim 2 wherein said jaws areformed along confronting surfaces with grooves engageable with saidobject whereby said object can entrain the other of said jaws with saidone of said jaws.
 7. The artificial hand defined in claim 2, furthercomprising a replaceable bridge disposed between the hinge quadranglesand formed with guide surfaces for stabilizing an object held in saidjaws.
 8. The artificial hand defined in claim 2 wherein said clampingjaws are formed as gripper plates replaceably mounted on the respectivehinge quadrangles.